The battalion chief, in turn, notified his dispatch office about 8:08 a.m. and requested fire department personnel and equipment to respond to Highland and Duffy Streets. En route to the site, the battalion chief observed flames and black smoke rising straight up in the air with no apparent wind. He arrived on-scene about 8:13 a.m. Mutual aid agreements were activated when the dispatch center was notified of the accident. As emergency response units and fire department personnel and equipment from adjacent jurisdictions arrived on scene, the battalion chief positioned them around the involved area. He had surveyed the accident area and determined that seven houses were fully engulfed in fire and that two houses were partially on fire. Being concerned with the downed power lines and the possibility of ruptured residential gas lines, the battalion chief requested the utility companies to shut down their respective lines. He also requested the water department to assist in building dikes to prevent the product from flowing into surrounding areas. The battalion chief ordered an evacuation of residents in the area; police personnel eventually evacuated about 170 persons in a four-block area. According to the deputy fire chief, because of fuel remaining on the ground, some residents were unable to return permanently to the area until August 6, 1989.

At 8:30 a.m., the deputy fire chief, who had been the incident commander during the response to the train derailment, arrived on scene and assumed the role of incident commander for this accident. By the time he arrived, fire-fighting operations and treatment and transportation of the injured to local hospitals had begun. At 10:05 a.m., a command post was set up at 2359 Mesa Street. According to testimony of the deputy fire chief, the mutual aid emergency response plan was implemented as planned. Although the deputy fire chief’s role as incident commander ended on May 28, fire department personnel remained on scene as a safety measure until May 31, 1989.

Pipeline Surveillance Operations

After Calnev’s maintenance superintendent observed the fire from his office window shortly after 8:00 a.m., he immediately notified the manager of operations who, along with other company personnel, proceeded to the accident site. Upon arrival at the accident site, the manager of operations introduced himself to the incident commander and was directed by the incident commander to fly with a police officer in a helicopter to observe the fire. Calnev’s manager of operations stated that while in the air, he observed a large stream of flaming liquid exiting the ground eastward at an angle of about 60 degrees from the horizontal. He stated that he observed substantial fire damage in the direction of the burning stream of liquid, a small pool of liquid burning around the rupture, and a small grass fire burning south of Highland Avenue. The manager of operations stated that he then advised the incident commander to allow the fire to burn itself out. According to the incident commander, the fire burned out by 3:30 p.m. on May 25.

According to Calnev’s manager of operations, when the fire was out, the rupture site was inspected and the damaged pipe examined (the damaged is described in the section "Damage," "Damage to the Pipeline"). At least four pieces of railroad debris—a brake arm, an approximately 8-inch section of I-beam from a locomotive, a piece of metal cowling from a locomotive, and a